A lean-to collapse has which characteristic?

A lean-to collapse has which characteristic?

• A. Pancake collapse
• B. V-shaped collapse
• C. Lean-to collapse
• D. A-frame collapse

Answer: (C)

Understanding collapse patterns helps you predict how debris will move and where to position safely. A lean-to collapse happens when one side of the structure fails and the remaining portion tilts toward that side, causing the debris to lean against an intact wall while the opposite side stays comparatively upright. This creates a leaning pile of material, a “lean-to” shape. It’s different from a pancake collapse, where floors fail flat in layers; from a V-shaped collapse, where walls tilt inward to form a V; and from an A-frame collapse, where the roof and walls fail to produce an A-like profile. So the described pattern matches a lean-to collapse.

Understanding collapse patterns helps you predict how debris will move and where to position safely. A lean-to collapse happens when one side of the structure fails and the remaining portion tilts toward that side, causing the debris to lean against an intact wall while the opposite side stays comparatively upright. This creates a leaning pile of material, a “lean-to” shape. It’s different from a pancake collapse, where floors fail flat in layers; from a V-shaped collapse, where walls tilt inward to form a V; and from an A-frame collapse, where the roof and walls fail to produce an A-like profile. So the described pattern matches a lean-to collapse.